Article

The objective of the present study was to compare cardiovascular and autonomic
responses to a mental stress test and to a maximal isometric exercise test
between offspring of normotensive (ON, n = 10) and hypertensive parents (OH, n =
10). Subjects underwent a 3-min Stroop Color Word Test and a maximal isometric
exercise test performed in an isokinetic dynamometer with continuous RR interval
monitoring. At rest, arterial pressure and heart rate were similar between
groups, but there was a significant reduction in total RR interval variance (ON:
5933 +/- 493 vs. OH: 2967 +/- 390 ms(2)) and an increase in low-high frequency
components ratio of heart rate variability (ON: 2.3 +/- 0.4 vs. OH: 4.6 +/- 0.8)
in OH group. In the first minute of the mental stress test and after both tests,
the OH group presented increased heart rate as compared with the ON group. After
both tests, only the ON group presented an increase in sympathetic component,
thus reaching resting values similar to those of the OH group. Our data
demonstrated increased resting cardiac sympathetic modulation in offspring of
hypertensive parents at similar levels to that observed in offspring of
normotensive parents after a mental stress test or a maximal isometric exercise
test. Additionally, the exacerbated heart rate responses to these physiological
tests in OH subjects may be associated with resting autonomic dysfunction, thus
reinforcing these evaluations as important tools for detecting early dysfunctions
in this genetically predisposed population.

Langue : ANGLAIS